Hypertensive kidney disease (Hypertensive nephrosclerosis)
Introduction
Hypertension is viewed as one of the most important causes of kidney disease. At the same time, kidney disease is the most common cause of secondary hypertension. In Norway, hypertension is stated as the most common cause of end-stage kidney failure (Stage 5D), and accounts for 1/3rd of patients. The prevalence of hypertensive disease (hypertensive nephrosclerosis) has increased greatly in the western countries the last ten years and is partially explained by improved survival rates among cardiovascular patients that now live long enough to develop kidney complications.
Causes
Microalubminuria is an early sign of organ damage due to hypertension. This is thought to represent a universal damage of endothelium in the whole vascular system. Both glomerular hypertension, that results in progressive glomerular damage, and tubular ischemia, that leads to tubulointerstitial damage, is thought to contribute to the histopathological changes seen in hypertensive nephrosclerosis.
Clinical presentation
Hypertensive nephrosclerosis is viewed as organ damage due to long-term hypertension. Established atherosclerotic vascular disease and left ventricle hypertrophy is often present and the probability increases with age. Proteinuria is normally a symptom (< 0,5 g/day), and the urine sediment is neutral, but hyaline and granular casts can be present. Other kidney diseases should be considered if proteinuria is over 1 g/day or active urine sediment is found. Biopsy of the kidney determines the final diagnosis, but the diagnosis is determined clinically in many patients when the risks to biopsy are deemed higher than the beneficial value of verifying the diagnosis.
Histopathology
One can see hyaline atherosclerosis in benign hypertension and hyperplastic atherosclerosis in malignant hypertension.
Prognosis and treatment
Hypertensive nephrosclerosis typically progresses slowly. There is no specific treatment. Blood pressure treatment with a target of 140/90 mmHg, as with all other kidney diseases, is the most important treatment for limiting the progression of kidney disease. ACE-inhibitors or AII blockers are the preferred antihypertensive drugs if tolerated.
Considering that the condition progresses slowly and the majority of patients have established atherosclerotic disease, the majority of patients will not reach end-stage kidney disease. Optimal cardiovascular secondary prophylaxis is indicated in this high-risk patient group.
Read more about hypertensive kidney disease
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